Sheeja E.,Herbal Drug Research Laboratory |
Joshi S.B.,Herbal Drug Research Laboratory |
Jain D.C.,Herbal Drug Research Laboratory
Pharmaceutical Biology | Year: 2010
Plumbago zeylanica Linn. (Plumbaginaceae) is used in the treatment of various inflammatory ailments in traditional medicines. In order to validate these ethnobotanical practices, the anti-inflammatory and antinociceptive activities of various leaf extracts (petroleum ether (60-80°), chloroform, acetone, ethanol, and aqueous) were studied using in vivo experimental models at two dose levels (200 and 400mg/kg, p.o.). Anti-inflammatory activity was tested using the carrageenan induced rat hind paw edema method while analgesic activity was studied using the hot plate and formalin induced models. Diclofenac (100mg/ kg) was used as the reference standard in both anti-inflammatory and analgesic models and morphine (10mg/ kg, i.p.) was used as the reference standard in the formalin induced analgesic model. The acetone extract significantly (p<0.01) reduced inflammation in the rats when compared to the control group. As for the analgesia effect, the acetone and petroleum ether extracts significantly (p<0.01) decreased the pain stimulus only in the later phase of the formalin test, suggesting that the drug could be peripherally acting. Bioassay-guided fractionation of the acetone extract led to the isolation and identification of plumbagin. Structure elucidation of plumbagin confirmed it as 5-hydroxy-2-methyl-1,4-naphthoquinone, a naphthaquinone derivative, through spectral techniques.